Inaki Relanzon / Cliffs and sea-stacks on the coast of "El Hierro" Island. Canary Islands, February 2011.

Sebastian Kennerknecht / Coastline at dusk, Shark Fin Cove, Davenport, California

Konrad Wothe / California Sea Lion (Zalophus californianus) at Cape Alava, Olympic National Park, Washington

Tim Fitzharris / Enderts Beach at sunset, Redwood National Park, California

Tim Fitzharris / Crashing surf on rocks at sunset, Point Piedras Blancas, California

Gary Bell/ Oceanwide / Sea stacks, Port Campbell National Park, Victoria, Australia

Theo Bosboom / Last rays of the sun through a hole in a Seastack with the Atlantic Ocean in the background. Sintra coast, Portugal, December

Jeff Foott / Seastack on coast, Ruby Beach, Olympic National Park, Washington

Norbert Wu / Sea stacks and beach at sunset, Olympic National Park, Washington

Norbert Wu / Sea stacks along coast at sunset, Olympic National Park, Washington

Norbert Wu / Sea stacks along coast, Olympic National Park, Washington

Norbert Wu / Sea stacks along coast, Olympic National Park, Washington